English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

A (3+1)-dimensional Einstein-Gauss-Bonnet effective description of gravityhas been recently formulated as the $D \to 4$ limit of the higher dimensionalfield equations after the rescaling of the coupling constant. This approach hasbeen recently extended to the four-dimensional Einstein-Lovelock gravity.Although validity of the regularization procedure has not been shown for thegeneral case, but only for a wide class of metrics, the black-hole solutionobtained as a result of such a regularization is also an exact solution in thewell defined 4D Einstein-Gauss-Bonnet theory suggested by Aoki, Gorji andMukohyama [arXiv:2005.03859] and in the scalar-tensor effective classicaltheories. Here we study the eikonal gravitational instability of asymptoticallyflat, de Sitter and anti-de Sitter black holes in the four dimensionalEinstein-Gauss-Bonnet and Einstein-Lovelock theories. We find parametricregions of the eikonal instability for various orders of the Lovelock gravity,values of coupling and cosmological constants, and share the code which allowsone to construct the instability region for an arbitrary set of parameters. Forthe four-dimensional Gauss-Bonnet black holes we obtain the region of stabilityin analytic form. Unlike the higher dimensional Einstein-Lovelock case, theeikonal instability serves as an effective cut-off of higher curvature Lovelockterms for the 4D black holes.

(In)stability of black holes in the 4D Einstein-Gauss-Bonnet and Einstein-Lovelock gravities